Phenolic compounds

Wine contains phenolic compounds (polyphenols) which give wine its characteristic colour and flavour and are produced by plants in response to fungal infection, ultraviolet light, and various chemical and physical stressors, especially during ripening. They are extracted from the seeds and skins of grapes during fermentation of winemaking, when the juice is in contact with the grape skins and seeds. The amount of polyphenols in red wine is generally greater than white wine because the red juice has longer contact with the grape skins during fermentation enabling more phenolic substances to be extracted into the red juice.

There is evidence that certain polyphenols, such as resveratrol, anthocyanins, flavonols and catechins in wine provide health benefits. Furthermore, rather than polyphenols themselves, their metabolites might be the real key players in cardiovascular and cancer protection. Researchers have shown that these polyphenols in wine act as antioxidants and are five times more potent than the benchmark antioxidant, vitamin E. These antioxidants are believed to reduce the damage caused by the body's free radicals (toxic waste products) which contribute to causing degenerative diseases in the body such as cancer, Alzheimer's disease, Parkinson's disease and ageing.

The polyphenols may also aid in inhibiting the oxidative transformation of ‘bad’ LDL cholesterol and thus, preventing the accumulation of this oxidised LDL cholesterol in the artery wall which eventually could block the blood flow and cause a heart attack or stroke.

These findings support the overwhelming and still growing body of scientific research indicating that moderate consumption of alcoholic beverages is associated with lower levels of coronary heart disease as well as with better health and lower mortality, especially when consumed in combination with a healthy diet.

The above summary provides an overview of the topic, for more details and specific questions, please refer to the articles in the database.

BACKGROUND: Mediterranean-style diet has been considered for its important beneficial effects on the progression of CV disease. Wine is an important component of the Mediterranean diet, and moderate wine drinkers have lower mortality rates than nondrinkers and heavy drinkers in epidemiologic studies. The beneficial effects of red wine are thought to be dependent on the polyphenol compounds such as resveratrol that exhibit potent antioxidant activity. However, white wine, although lacking polyphenols, contains simple phenols, such as tyrosol (Tyr) and hydroxytyrosol (OH-Tyr), characteristic also of extra-virgin olive oil, which may share similar antioxidant and inflammatory properties. PATIENTS AND METHODS: The effect of white wine and extra-virgin olive oil on inflammatory markers was evaluated in 10 healthy volunteers and in 10 patients…

In humans, urinary hydroxytyrosol (OHTyr) concentrations have been associated to alcohol and wine consumption. To explore the role of wine components on promoting an endogenous OHTyr generation we performed a cross-over, double-blind, randomized controlled clinical trial (n = 28 healthy volunteers). Ethanol (wine and vodka), dealcoholized wine, and placebo were administered. Alcohol, dealcoholized wine, and particularly wine promoted a de novo OHTyr generation in vivo in humans. Potential OHTyr precursors (tyrosine, tyrosol, tyramine) were investigated in rats. Tyrosol was metabolized to OHTyr. Collating both studies, it is postulated that an increased Tyr bioavailability, a shift to a reductive pathway in dopamine and tyramine oxidative metabolism, and the biotransformation of Tyr to OHTyr were mechanisms involved in the OHTyr endogenous generation.

SCOPE: Grape seed polyphenol extract (GSPE) is receiving increasing attention for its potential preventative and therapeutic roles in Alzheimer's disease (AD) and other age-related neurodegenerative disorders. The intestinal microbiota is known to actively convert many dietary polyphenols, including GSPE, to phenolic acids. There is limited information on the bioavailability and bioactivity of GSPE-derived phenolic acid in the brain. METHODS AND RESULTS: We orally administered GSPE to rats and investigated the bioavailability of 12 phenolic acids known to be generated by microbiota metabolism of anthocyanidins. GSPE treatment significantly increased the content of two of the phenolic acids in the brain: 3-hydroxybenzoic acid and 3-(3 -hydroxyphenyl)propionic acid, resulting in the brain accumulations of the two phenolic acids at micromolar concentrations. We also…

Alzheimer's disease (AD) is a devastating disorder that strikes 1 in 10 Americans over the age of 65, and almost half of all Americans over 85years old. The odds of an individual developing AD double every five years after the age of 65. While it has become increasingly common to meet heart attack or cancer survivors, there are no AD survivors. There is mounting evidence that dietary polyphenols, including resveratrol, may beneficially influence AD. Based on this consideration, several studies reported in the last few years were designed to validate sensitive and reliable translational tools to mechanistically characterize brain bioavailable polyphenols as disease-modifying agents to help prevent the onset of AD dementia and other neurodegenerative disorders. Several research groups worldwide…